| 1 |
578 |
markom |
'\"
|
| 2 |
|
|
'\" Copyright (c) 1990-1992 The Regents of the University of California.
|
| 3 |
|
|
'\" Copyright (c) 1994-1996 Sun Microsystems, Inc.
|
| 4 |
|
|
'\"
|
| 5 |
|
|
'\" See the file "license.terms" for information on usage and redistribution
|
| 6 |
|
|
'\" of this file, and for a DISCLAIMER OF ALL WARRANTIES.
|
| 7 |
|
|
'\"
|
| 8 |
|
|
'\" RCS: @(#) $Id: update.n,v 1.1.1.1 2002-01-16 10:25:25 markom Exp $
|
| 9 |
|
|
'\"
|
| 10 |
|
|
.so man.macros
|
| 11 |
|
|
.TH update n 7.5 Tcl "Tcl Built-In Commands"
|
| 12 |
|
|
.BS
|
| 13 |
|
|
'\" Note: do not modify the .SH NAME line immediately below!
|
| 14 |
|
|
.SH NAME
|
| 15 |
|
|
update \- Process pending events and idle callbacks
|
| 16 |
|
|
.SH SYNOPSIS
|
| 17 |
|
|
\fBupdate\fR ?\fBidletasks\fR?
|
| 18 |
|
|
.BE
|
| 19 |
|
|
|
| 20 |
|
|
.SH DESCRIPTION
|
| 21 |
|
|
.PP
|
| 22 |
|
|
This command is used to bring the application ``up to date''
|
| 23 |
|
|
by entering the event loop repeated until all pending events
|
| 24 |
|
|
(including idle callbacks) have been processed.
|
| 25 |
|
|
.PP
|
| 26 |
|
|
If the \fBidletasks\fR keyword is specified as an argument to the
|
| 27 |
|
|
command, then no new events or errors are processed; only idle
|
| 28 |
|
|
callbacks are invoked.
|
| 29 |
|
|
This causes operations that are normally deferred, such as display
|
| 30 |
|
|
updates and window layout calculations, to be performed immediately.
|
| 31 |
|
|
.PP
|
| 32 |
|
|
The \fBupdate idletasks\fR command is useful in scripts where
|
| 33 |
|
|
changes have been made to the application's state and you want those
|
| 34 |
|
|
changes to appear on the display immediately, rather than waiting
|
| 35 |
|
|
for the script to complete. Most display updates are performed as
|
| 36 |
|
|
idle callbacks, so \fBupdate idletasks\fR will cause them to run.
|
| 37 |
|
|
However, there are some kinds of updates that only happen in
|
| 38 |
|
|
response to events, such as those triggered by window size changes;
|
| 39 |
|
|
these updates will not occur in \fBupdate idletasks\fR.
|
| 40 |
|
|
.PP
|
| 41 |
|
|
The \fBupdate\fR command with no options is useful in scripts where
|
| 42 |
|
|
you are performing a long-running computation but you still want
|
| 43 |
|
|
the application to respond to events such as user interactions; if
|
| 44 |
|
|
you occasionally call \fBupdate\fR then user input will be processed
|
| 45 |
|
|
during the next call to \fBupdate\fR.
|
| 46 |
|
|
|
| 47 |
|
|
.SH KEYWORDS
|
| 48 |
|
|
event, flush, handler, idle, update
|
